migrate to the thymus where they mature, releases cytokine, able to detect agents within a cell
cytotoxic: recognizes virus-infected cells causing them to lyse
Helper: encourages t cells and b cells to divide

B cells

circulate and collect in the lymph nodes, secretes antibodies, recognizes a certain shape of composition

Plasma

made from B cells

cytokines

proteins release by t cells, bind to alter the behavior of their target cells

complement protein

antimicrobial proteins, causes fluid to enter these foreign cells to cause them to burst

interferons

produced by cells that are infected by a virus, increases the resistance of neighboring cells to infections

evolution of the lung like sacs set the stage for organism to move onto land, aloowing them to breathe air and leave water temporary, changes in fin structure allowed fish to move onto land, fish evolved into amphibians, reptiles, birds, mammals

amniotic egg

shells made out of calcium and prevent the evaporation of fluids inside yet allows oxygen and carbon dioxide to pass, allows the embryo to reach advance stages before hatching